title: Early transcriptional responses of internalization defective Brucella abortus mutants in professional phagocytes, RAW 264.7.
abstract: BACKGROUND
  Brucella abortus is an intracellular zoonotic pathogen which causes undulant fever, endocarditis, arthritis and osteomyelitis in human and abortion and infertility in cattle. This bacterium is able to invade and replicate in host macrophage instead of getting removed by this defense mechanism. Therefore, understanding the interaction between virulence of the bacteria and the host cell is important to control brucellosis. Previously, we generated internalization defective mutants and analyzed the envelope proteins. The present study was undertaken to evaluate the changes in early transcriptional responses between wild type and internalization defective mutants infected mouse macrophage, RAW 264.7.
  
  
  RESULTS
  Both of the wild type and mutant infected macrophages showed increased expression levels in proinflammatory cytokines, chemokines, apoptosis and G-protein coupled receptors (Gpr84, Gpr109a and Adora2b) while the genes related with small GTPase which mediate intracellular trafficking was decreased. Moreover, cytohesin 1 interacting protein (Cytip) and genes related to ubiquitination (Arrdc3 and Fbxo21) were down-regulated, suggesting the survival strategy of this bacterium. However, we could not detect any significant changes in the mutant infected groups compared to the wild type infected group.
  
  
  CONCLUSIONS
  In summary, it was very difficult to clarify the alterations in host cellular transcription in response to infection with internalization defective mutants. However, we found several novel gene changes related to the GPCR system, ubiquitin-proteosome system, and growth arrest and DNA damages in response to B. abortus infection. These findings may contribute to a better understanding of the molecular mechanisms underlying host-pathogen interactions and need to be studied further.
authors.affiliation: Department of Infectious Diseases, College of Veterinary Medicine, Brain Korea 21 for Veterinary Science, Seoul National University, Seoul 151-742, South Korea.
authors.forename: Seung Bin
authors.initials: SB
authors.lastname: Cha
authors.forename: Won Jung
authors.initials: WJ
authors.lastname: Lee
authors.forename: Min Kyoung
authors.initials: MK
authors.lastname: Shin
authors.forename: Myung Hwan
authors.initials: MH
authors.lastname: Jung
authors.forename: Seung Won
authors.initials: SW
authors.lastname: Shin
authors.forename: An Na
authors.initials: AN
authors.lastname: Yoo
authors.forename: Jong Wan
authors.initials: JW
authors.lastname: Kim
authors.forename: Han Sang
authors.initials: HS
authors.lastname: Yoo
mesh_terms: D000818:Animals; D002003:Brucella abortus / Q000235:genetics* / Q000502:physiology*; D002460:Cell Line; D020869:Gene Expression Profiling; D008264:Macrophages / Q000166:cytology / Q000382:microbiology*; D051379:Mice; D058977:Molecular Sequence Annotation; D009154:Mutation / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D015203:Reproducibility of Results; D013997:Time Factors; D014158:Transcription, Genetic